RecoTau/plugins/RecoTauTwoProngFilter.cc

0001 /*
0002  * ===========================================================================
0003  *
0004  *       Filename:  RecoTauTwoProngFilter
0005  *
0006  *    Description:  Modify taus remove low-pt second prongs
0007  *
0008  *         Author:  Evan K. Friis (UC Davis)
0009  *
0010  * ===========================================================================
0011  */
0012
0013 #include "RecoTauTag/RecoTau/interface/RecoTauBuilderPlugins.h"
0014 #include "RecoTauTag/RecoTau/interface/RecoTauCommonUtilities.h"
0015
0016 namespace reco {
0017   namespace tau {
0018
0019     namespace {
0020       // Delete an element from a ptr vector
0021       std::vector<CandidatePtr> deleteFrom(const CandidatePtr& ptr, const std::vector<CandidatePtr>& collection) {
0022         std::vector<CandidatePtr> output;
0023         for (std::vector<CandidatePtr>::const_iterator cand = collection.begin(); cand != collection.end(); ++cand) {
0024           if ((*cand) != ptr)
0025             output.push_back(*cand);
0026         }
0027         return output;
0028       }
0029     }  // namespace
0030
0031     class RecoTauTwoProngFilter : public RecoTauModifierPlugin {
0032     public:
0033       explicit RecoTauTwoProngFilter(const edm::ParameterSet& pset, edm::ConsumesCollector&& iC);
0034       ~RecoTauTwoProngFilter() override {}
0035       void operator()(PFTau&) const override;
0036
0037     private:
0038       double minPtFractionForSecondProng_;
0039     };
0040
0041     RecoTauTwoProngFilter::RecoTauTwoProngFilter(const edm::ParameterSet& pset, edm::ConsumesCollector&& iC)
0042         : RecoTauModifierPlugin(pset, std::move(iC)) {
0043       minPtFractionForSecondProng_ = pset.getParameter<double>("minPtFractionForSecondProng");
0044     }
0045
0046     void RecoTauTwoProngFilter::operator()(PFTau& tau) const {
0047       if (tau.signalChargedHadrCands().size() == 2) {
0048         const std::vector<CandidatePtr>& signalCharged = tau.signalChargedHadrCands();
0049         size_t indexOfHighestPt = (signalCharged[0]->pt() > signalCharged[1]->pt()) ? 0 : 1;
0050         size_t indexOfLowerPt = (indexOfHighestPt) ? 0 : 1;
0051         double ratio = signalCharged[indexOfLowerPt]->pt() / signalCharged[indexOfHighestPt]->pt();
0052
0053         if (ratio < minPtFractionForSecondProng_) {
0054           CandidatePtr keep = signalCharged[indexOfHighestPt];
0055           CandidatePtr filter = signalCharged[indexOfLowerPt];
0056           // Make our new signal charged candidate collection
0057           std::vector<CandidatePtr> newSignalCharged;
0058           newSignalCharged.push_back(keep);
0059           std::vector<CandidatePtr> newSignal = deleteFrom(filter, tau.signalCands());
0060
0061           // Copy our filtered cand to isolation
0062           std::vector<CandidatePtr> newIsolationCharged = tau.isolationChargedHadrCands();
0063           newIsolationCharged.push_back(filter);
0064           std::vector<CandidatePtr> newIsolation = tau.isolationCands();
0065           newIsolation.push_back(filter);
0066
0067           // Update tau members
0068           tau.setP4(tau.p4() - filter->p4());
0069           tau.setisolationPFChargedHadrCandsPtSum(tau.isolationPFChargedHadrCandsPtSum() - filter->pt());
0070           tau.setCharge(tau.charge() - filter->charge());
0071           // Update tau constituents
0072           tau.setsignalChargedHadrCands(newSignalCharged);
0073           tau.setsignalCands(newSignal);
0074           tau.setisolationChargedHadrCands(newIsolationCharged);
0075           tau.setisolationCands(newIsolation);
0076         }
0077       }
0078     }
0079   }  // namespace tau
0080 }  // namespace reco
0081 #include "FWCore/Framework/interface/MakerMacros.h"
0082 DEFINE_EDM_PLUGIN(RecoTauModifierPluginFactory, reco::tau::RecoTauTwoProngFilter, "RecoTauTwoProngFilter");